Stall cock of milking machines



Patented `luly 29, 1941 STALL COCK F MILKING MACHINES Walter A. Scott,Poughkeepsie, N. Y., assigner to The De Laval Separator Company, NewYork, N. Y., a corporation of New Jersey Application January 19, 1940,Serial No. 314,641

(Cl. E11-58) 4 Claims.

My invention relates to so-callecl stall cocks used on vacuum lines,extending through a cow barn, for the attachment of iiexible pipebranches connected with the individual milking machines of a milkingmachine installation.

The object of my invention is to provide a simple and efcient cock oflow cost and that is unlikely to get out of order.

While the invention is adapted for use in milking machines which areoperable wholly pneumatically, it is also adapted for use in thosemilking machines which require also the establishment of a connectionwith a source of electric power. My invention, therefore, also comprisesmeans whereby, when the attachment of a pipe branch to the main vacuumline is effected, such electric connection will be simultaneouslyestablished.

The construction of my improved stall cock and its mode of operationwill be best understood by reference to the annexed drawing, whichillustrates a preferred embodiment of the invention and in which- Fig. 1is a longitudinal section of a stall cock embodying my invention.

Fig. 2 is a plan View showing the means for effecting an electricalconnection.

Fig. 3 is a perspective View of the lever that forms part of the cock.

Fig. 4 is a cross section of the end of the flexible tube adapted toconnect a milking machine unit, through the stall cock, with the vacuumpipe line.

The body oi my improved stall cock is in the form of a T with a tubularstem I and a head 2 having a large bore 3 extending from one end pastthe junction with the stem I and a smaller bore 4 extending from the endof the large bore to the other end of the head. The end with the smallerbore is externally threaded at 5 for screw connection with a vacuum pipeline 3|.

At the junction of the large and small bores of the cock body is a valveseat 6 against which a soft washer 'I on a valve body 8 is pressed by aspring 9, whose other end is held in a socket I0 in a plug Il screwedinto the more distant end of the large bore 2. A soft washer I2 may beused to make the plug II air tight.

Within the stem I is a lever I3 with a fulcrum Ill bearing against theinside of the stem and a portion I5 with a sloping edge I6 projectingthrough a slot I'I in the opposite wall of the stem. The other end ofthe lever has a fork with two prongs I8 adapted to rit in a groove I9around the stem of the valve 8, and, at the inner end of the slot, anupturned tongue 20 which rests against the side of the stem of the valveand inside the spring 9 and prevents movement of the lever away from thevalve stem.

With the threaded end 5 screwed into a pipe line in which a partialvacuum exists, air pressure on top of the Valve 8 assists the spring 9in holding the valve against the seat 6 and preventing entrance of airinto the vacuum pipe line.

The end of the flexible tube 26, which connects with a milking machineunit, is preferably provided with a metallic ferrule 2T having a flangedend adapted, when the tube, with the ferrule inside it, is slipped orforced onto the stem I of the cock, to engage a soft ring 30 around theneck of the stem, thereby assisting in making an airtight joint betweenthe stem and the errule.

When the flexible tube 26 is engaged with the stem I as just described,it will, as it slides along the sloping edge I6, force the outer end ofthe lever I3 down. The inner end will then move up and raise the Valve8, with its washer l, away from the seat 6 and open communication fromthe stem I and the attached tube 26 to the inside of the pipe line andthus exhaust air from the tube and the connected milking unit. Upon thewithdrawal, after completion of milking, of the tube 26 from the stem ofthe cock, the spring 9 seats the valve 8, and the lever I3 is returnedto the position shown in Fig. 1.

With milking machine units requiring, preliminary to operation, inaddition to connection with a partial vacuum, a connection with a sourceof electric power, the following means are provided to close theelectric circuit simultaneously, or approximately simultaneously, withthe establishment of the vacuum connection above described. A contactmember, preferably a spring 2|, is clamped by screws 22 betweeninsulating pieces 23 and has a wire 24 connected with a source of power(not shown). Tube 26 has a metallic collar 25 which, when the tube isforced onto the stem I as hereinbefore described, contacts with spring2l. Wires 28 and 29, connected respectively with collar 25 and ferrule21, lead to any electrically operable device that may be embodied in themilking machine unit with which tube 25 is connected. In the connectionof the tube 26 with the stall cock the circuit is completed, from thesource of electric power (not shown), through wire 24, contact spring2I, collar 25, wire 28 to the milking machine unit, wire 29 from themilking machine unit, ferrule 21, the metal of the cock and thencethrough the vacuum pipe line to the source of electric power,

What I claim and desire to protect by Letters Patent is:

l. A stall cock for milking machine installations comprising a body inthe form of a hollow T having two ends and a branch, one of said endsbeing adapted for connection with a pipe linel a cap closing the otherof said ends, the branch being adapted to have a hose slipped over it, acompressible packing against which said hose is adapted to make a tightjoint, a check valve within the body adapted when seated to closecommunication from the body to the pipe line, a lever fulcrumed withinthe branch and extending lengthwise thereof and having a portion soprojecting through a slot in the branch that a hose slid over the branchwill swing the lever on its ulcrum, and means operative to unseat thevalve when the lever is so operated.

2. A stall cock for milking machine installations comprising a body inthe form of a hollow T having two ends and a branch, one end beingadapted for connection with a pipe line and the other end being closedand having a valve seat at its junction with the rst named end, thebranch being adapted to make an air tight joint with a tube slipped overit, a valve Within the body adapted to cooperate with the seat and closecommunication between the body and said pipe line, a lever fulcrumedwithin the branch having on one end a portion adapted to project througha slot in the branch so as to be depressed by a tube slipped over it,and means at the other end of the lever adapted to raise the valve fromthe seat when the rst end is depressed.

3. A stall cock ior milking machine installations comprising a body inthe form of a T with a hollow stem and, at right angles thereto, a bodyhaving a bore with large and small diameter portions and a valve seat atthe junction of the two portions, a valve adapted, when in contact withthe seat, to close communications from the large to the small bore, alever, fulcrumed within the branch, having at one end a portionprojecting through a slot therein so as to be depressed when a tube isslipped thereover, a fork at the other end of the lever adapted tocooperate with a groove around the valve stem to raise the valve fromits seat when the rst mentioned end is depressed, a tongue upturned atthe side of the valve stem, a closure for the large bore, and a coilspring having one end abutting against said closure and the other endabutting against the fork of the lever to press it and the valve towardthe seat and, by surrounding the valve stem and tongue, prevent movementof the lever away from the valve stem.

4. A stall cock for milking machine installations comprising a body inthe form of a T having a hollow stem adapted to make an air tightconnection with a tube slipped thereover and a head having one endadapted for connection with a pipe line, a large bore extending from theother end past the opening from the branch and having a removableclosure at the end, a smaller bore extending from the termination of thelarge bore through the rst mentioned end of the head, there being avalve seat at the junction of the large and small bores, a valve andmeans to press it toward the seat to thereby close communcation betweenthe large and small bores, and a lever, fulcrumed in the stem, with oneend projecting through a slot therein so as to be depressed when a tubeis slipped thereover and the other end so connected with the valve as toraise it from its seat and open communication between the large andsmall bores when the first end of the lever is depressed.

WALTER A. SCOTT.

